North Korea has said it successfully test-fired a newly developed ballistic missile from a submarine.

Kim Jong-un personally attended the test launching of what he described as a “world-level strategic weapon”, the official Korean Central News Agency said. The report did not reveal the timing and location of the launch. A day earlier the North accused the South of breaching its maritime territories and threatened to launch attacks on ships.

The regime leader praised the test launch as an “eye-opening success” and declared it gave North Korea a weapon capable of “striking and wiping out in any waters the hostile forces infringing upon the sovereignty and dignity of [North Korea].”

On Kim’s orders the submarine submerged and fired the missile from underwater into the sky, the agency said.

South Korea’s defence ministry said in 2014 that it believed the North was developing technologies for launching ballistic missiles off submarines.

A US research institute said in January that such capability posed a potential new threat to South Korea, Japan and US bases in east Asia, although North Korea’s submarines tend to be old and would be vulnerable to attack.

There has been expectations that Kim would attend the Victory Day celebration in Russia on Saturday for his international debut, but North Korea has sent to Moscow the head of its parliament instead.